Means for opening and closing circuits at regular intervals



Aug. 14, 1934. c v BATEs 1,970,412

7 MEANS FOR OPENING AND CLOSING CIRCUITS AT REGULAR INTERVALS Filed May 16, 1933 2 Sheets---Sheet l INVENTOR.

Lwafi BY L A a. M ATTORNEY.

Aug. 14, 1934. c. v. BATES 1,970,412

MEANS FOR OPENING AND CLOSING CIRCUITS AT REGULAR INTERVALS Filed May 16, 1935 2 Sheets-Sheet 2 I (12 2/ l l q l 1 h h r, f Git/fond 217361166.

J BY

c I I 6 I s 7 ATTORNEY.

Patented Aug. 14, 1934 UNITED STATES PATENT OFFICE MEANS FOR OPENING AND CLOSING GIR- CUITS AT REGULAR INTERVALS 15 Claims.

My invention relates to improvements in means for opening and closing circuits at regular intervals, such devices being known as magnetic periodic switches.

Switches of this character are useful in many fields, as for example the transmission of time signals, the actuation of clock mechanism or the flashing of warning lights. The apparatus described herein, as illustrating the invention, is adapted particularly for flashing street traific signals or warning red lights.

The main object of the invention is to provide a dependable electrically operated mechanism, requiring almost no attention over long intervals of time.

Another object is to provide mechanism of this character, the moving parts of which are so light and well balanced and the circuit closing mechanism so timed, that the electric energy required to operate it continuously is so minute that a small pocket battery may be used for the purpose.

An additional object is to provide a device in which the local operating circuit controls a second or work circuit, which latter may have an independent source of current of much larger value than the local circuit, with contacts of corresponding current carrying capacity and operated magnetically without direct mechanical connections.

A further object is to provide such a device with contacts installed in a container exhausted of air, whereby said contacts are prevented from deteriorating.

An additional object is to provide equipment of this character in which the'sealed in contacts control not only the local circuit but the external circuit as well.

Another object is to provide a small, light, compact instrument for the purpose specified, which is not deranged by vibration, but which, on the contrary is practically self starting when vibrated or jarred, which need not necessarily be mounted on a support which is exactly horizontal for successful operation and which will operate for months and even years at a time without any attention.

Further objects and advantages will be apparent from the following description of several embodiments of the invention which are illustrated in the drawings, in which Fig. 1 is a front elevation of a commercial instrument;

Fig. 2 is a side elevation of the supporting frame with certain parts omitted;

Fig. 3 is a rear elevation of the instrument;

Fig. 4 is a perspective view, on a larger scale, of an oscillating shaft and associated parts;

Fig. 5 is an enlarged elevation of a contact supporting member;

Fig. 6 is a side view thereof;

Fig. '7 is an enlarged elevation of circuit closing contacts in one position;

Fig. 8 is a similar elevaton with the parts in another position; 5 Fig. 9 is a front elevation of a modified instrument;

Fig. 10 is a central section thereof on line 1010 of Fig. 9;

Fig. 11 is an enlarged section of the bearing for the oscillating shaft;

Fig. 12 is a diagram of the parts in one position;

Fig. 13 is a similar diagram with the parts in another position;

Fig. 14 is a representation of the field of a permanent magnet constituting one of the elements of the structure; and

' Fig. 15 is a diagram of a further modification.

The mechanism may be mounted on any suit- 30 able base 10 such as a hollow insulating structure in which a small battery 11 may be concealed. As shown in Fig. 10, the battery may be releasably held in place by a clip 12 to permit ready installation and renewal. 35

In the form shown in Figs; 1 to 8 inclusive, the various parts of the device are located on a supporting plate 13, having legs 14 secured to the base. A smaller plate 15 is arranged to the rear of the plate 13, being spaced therefrom by shouldered rivets 16. The main plate has a bracket or arm 17 mounted on the front face thereof by means of small lugs 18 held by screws, as shown in Figs. 1 and 2. Suitable bearings 19 are mounted in said arm 17 and in said plate 15 respectively as shown also in Fig. 2.

Mounted in said bearings is a small, light shaft 20 having discs 21 near-its ends, beyond which are knife edged supports 22 to permit said shaft to oscillate with little or no friction. As shown in Fig. 11, each knife edge rests in a sector shaped opening in a small, hard plate 23, made preferably of steel, one of which it fitted in each of the bearings 19. Endwise movement of said shaft is prevented by small steel discs 24 which are spaced from the plates 23 by brass rings 25.

The shaft 20 has a cross arm 26 fixed thereto and a depending arm 27 with a weightl28 adjustably secured thereto, as shown in Fig. 4.

This cross arm carries a permanent magnet in the form of an are shaped steel bar or rod, preferably in the form of an interrupted steel ring 29, as shown in Fig. 1, the gap in the 'ring being shown at the bottom with the adjustable weight between the ends of the magnet. Said magnet may be held in said cross arm by small clips 30 held in place by screws as in Fig. 1.

The shaft and-the magnet carried thereby are adapted to oscillate back and forth, said magnet passing through the coil but out of contact therewith, said coil constituting an electro-magnet adapted to be connected in circuit intermittently at regular intervals, as hereinafter described, to cause continued oscillation of said ring and associated parts. Said coils is wound with very fine wire, for example No. 44 wire, having about eight thousand five hundred turns,

and with a high resistance, which may, for ex-' ample, be about four thousand ohms. The amount of current necessary to energize such magnet is exceedingly small, as for example one ten thousandth of an ampere.

In Figs. 12, 13 and 14, the coil and interrupted ring are shown somewhat diagrammatically to render their cooperation clearer. The ring is magnetized in such a way that the two ends constitute like poles, the middle of the arc representing the opposite pole. The drawing illustrates approximately the lines of force as indi-- cated by the position assumed by iron filings on a sheet of paper laid over one of the rings.v

When current flows momentarily through the coil, the latter has a definite polarity with the result that there is a tendency for'the ring and its supporting shaft to rotate. With the particular connections shown in the other figures, the ring may be assumed to rotate in a counterclockwise direction whenever the coil is energized. After a short angular movement the circuit is opened, as hereinafter described more in detail, and the weight of the parts causes the same to swing back toward and past initial position, the center of gravity being below the pivotal support. For example, energization of the coil causes a movement to or beyond the position shown in Fig. 13, deenergization of the coil permits the ring to swing back to or beyond the position shown in Fig. 12, and successive energization of the coil at regular intervals provides the necessary impulse to keep up the oscillations indefinitely.

This oscillating movement is used to accomplish two functions. First, the magnetized ring causes theopening and closing of a circuit, preferably through cooperating contacts located in an adjacent sealed container, by magnetically influencing a permanent magnet in said container. Second, said oscillations are used to open and close the circuit from the battery, located in the base of the instrument or elsewhere, to the coil 31 to provide the necessary impulses to insure continuous operation. Re

ferring first to the device for opening and closing the external circuit controlled by the instrument, the parts are enclosed in a suitable container 32 which may be of glass with the parts sealed therein. The container is mounted in a seat formed by bending around the end 33, of a strip of metal 34, which is pivotally mounted on the plate 13 by means of a small bolt or the like 35 and frictionally clamped in place, whereby said arm may be adjusted by moving it, to a certain extent, about said pivot, as for example in the position indicted in dotted 1 .11 5

in Fig. 3. This circuit contacts within the sealed container may be of the same character as those illustrated in 'my copending application 637,407, filed October 12, 1932.

Briefly stated, a permanent magnet 36 within said container is pivotally mounted at 37 to brackets on a metal support 38. Said magnet may therefore be oscillated about its pivotal support by the oscillation of the ring magnet adjacent thereto. The enclosed magnet carries a metal contact 39 which opens and closes the circuit represented by terminals 40-40, sealed in the glass and from which conductors lead to the binding posts 41 on the base. is exhausted from said glass tube to prevent corrosion. It will be seen that this circuit has no connection with the circuit of the battery 11. It depends on an external source, such as a storage battery, whereby any suitable external circuit may be opened and closed at regular intervals to operate a flasher or warning traffic signal, or for any other purpose.

The operation of the device for opening and closing the circuit to the coil 31 will now be described. As shown in Fig. 1, one terminal of said coil has a conductor 42 leading therefrom which connects with one of the battery termi- 'nals (not shown) and another conductor 43 connects the other terminal of the coil with the metallic supporting plate 13 to ground it. Another terminal of the same circuit is shown at 44 where one end of a light, conducting spring 45 is secured, the other end being connected to the shaft 20. See Fig. 4. The circuit also includes a contact arm 46 on said shaft with a contacting pin 47 thereon, made preferably of silver. Said pin contacts with one side of a notch in a silver plate 48, shown in Fig. 5 as mounted on a thin, light, insulating support 49, which latter is mounted on a conducting shaft 50 with the silver plate in contact therewith. It will be noted that in Fig. 5 where the parts are shown on an enlarged scale, the insulating support 49 is also notched adjacent the upper notch in the silver plate 48 but that said notches do not register, one being displaced sideways with reference to the other. Thus, when the pin 47 oscillates back and forth in said notches, it engages the conducting plate when vit swings in one direction and engages the insulating support when it swings in the other direction so that the circuit is closed only when said pin swings to the right, and then for only part of its swing. The cooperation of the parts is illustrated in Figs. 7 and 8, as shown by the two different positions assumed.

The shaft 50 is supported in small hearings in the plates 13 and 15, being mounted at one end in a strip of insulating material 51 covering an opening in the plate 13 (see Fig. l) and passing through a strip of insulating material 52 secured to the plate 13, as shown in Fig. 3, and spanning an opening in the latter also. A hair spring 53 has one end in engagement with the shaft 50 and the other end secured to a small contacting arm 54, bolted at 55 to said insulating support 52. Another arm 56, secured at the same point, carries a very light rod 57 with a small weight 58 thereon, which rod rests in a groove in the shaft 50 (see Fig- 6) and creates enough friction to hold the sheet of insulating material 49 in either of its two extreme positions as the pin 47 moves in and out of the notch in the upper part thereof, as shown in Figs, 7 and 8. One end of said shaft The air I is received loosely within a guide 59,

struck up from the plate 15 The bolt constitutes another circuit termi nal from which a conductor leads to the battery, said conductor passing through an opening 61 in the upper part of the base (see Fig. 10)

through which opening the conductor 42 also passes to the battery.

From the foregoing it willfbe seen that contact is maintained between the pin 47 and the notched plate 48 during the time when the magnetized ring is swinging from normal position, shown in Fig. 1, to the position shown in Fig. 13, at which point the circuit is broken and remains open during the return movement of said ring to and beyond the position shown in Fig. 12. On the reverse movement said pin engages said plate when the parts have reached approximately the position indicated in Fig. 12 and the contact is closed during the swinging movement from that position to the position shown in Fig. 13. It will be noted that the pin.

has a wiping contact against the edge of the silver plate, thus insuring a clean contact. As the parts are very light and well balanced, there is very little friction to retard the oscillations of the ring magnet. To increase the speed of operation, the adjustable weight 28 may be lowered or a weight may otherwise be added to the lower part of the structure. To slow down the operation, the weight may be raised or reduced. With the center of gravity nearer the center of rotation, the oscillations are slower as the device is more nearly balanced.

Thus it will be seen that the circuit which includes the battery and the coil, is opened and closed at regular intervals by contact members controlled by the oscillation of the magnetized ring. The contacts in the sealed container 32 which control the external circuit are also opened and closed at regular intervals during a definite portion of the oscillations of said magnetized ring. If the supporting arm 34 for said sealed container is swung upwardly about its pivotal support, as indicated in dotted lines in Fig. 3, the external circuit is closed for shorter intervals of time. For example, when the magnetized ring is in the position shown in Fig. 13, said sealed-in contacts are separated but they are brought together as said magnetized ring swings in clockwise direction toward the position shown in Fig. 12, and they are separated on the reverse movement. It will be apparentthat'if the permanent magnet within said sealed container is swung upwardly to the dotted line position, the portion of the magnetized ring and the accompanying lines of force which cause it to move do not approach-it until a later part of the swing, and conversely they recede earlier. Therefore, the contacts in the sealed container remain closed for a shorter interval of time as said arm is swung upwardly from its normal position. The frequency with which the cycle repeats itself is regulated by adiusting the weight 28 up or down on its screw threaded stem asstated above.

The current-consumption of the instrument is extremely low. One reason, as previously stated, is that the magnet coil will develop sufllcient impulse on an exceedingly small current, in

addition to which the circuit from the battery is closedIfor a very small interval of time, for example about one-fifth of a second, with the instrument described. As shown in Fig. 14, the lines of force which extend practically at right angles to the ring magnet, are of maximum density near the middle part of said ring, 1. e. at the top, and therefore, movement of this magnetic field through the coil builds up a counter. E. M. F. which opposes that impressed on the coil by the battery, the net result being a very small current flow. A very inexpensive type of dry battery will sufiice as the'source of current supply, for example, the pocket size, possibly two or three inches long. Such batteries, which sell in many stores for ten cents, will operate the instrument continuously for more than a year. The maximum current necessary for the instrument illustrated is as low as three ten thousandths of a milliampere, representing a short circuit on a one and one-half volt battery.

When the instrument is not in operation, the magnetized ring and the shaft on which it is mounted, may be lifted slightly by swinging a-curved brass trough 62 about the central horizontal axis of the .coil 31. This brass member fits within the cylindrical opening in said coil and underlies the magnetized ring but is normally out of contact therewith except when the projecting arms 63 are swung downwardly, whereupon the diagonally cut ends of said trough serve as a cam to lift the ring to bring the brass discs 21 on the shaft 20 (see Fig. 4) into frictional engagement with the upper parts of the cylindrical bearing members 19 (see Fig. 11) Thus the ring is prevented by friction from oscillating and the knife lifted from their supports.

One advantage of the device is that it is not adversely influenced in its operation by vibration, and, furthermore, need not rest on a support which is level, although it is preferable to have it nearly level. Also, it is practically self starting, that is to say it is difficult to move it to such a position that it will discontinue its oscillations as a slight jar of vibration will cause the oscillations to begin, whereupon they pick up to the normal amount.

In the other form of instrument, illustrated in Figs. 9 and 10, the circuit contacts in the sealed container not only control the external circuit but also control the circuit to .the coil which maintains the oscillations of the magnetized ring. Thus the additional contacts required in the operation of the first form of instrument described, is eliminated. Furthermore, the only contacts which are employed are protected in a sealed tube from which the air has been exhausted, thereby insuring against corrosion.

In describing this modified form of instrument, the same references have been applied as in Fig. 1 to 8 inclusive, insofar as the parts are substantially the-same. The supporting plate 13 in Fig. 10 has the hub 19 mounted directly thereon instead of on an auxiliary plate at the rear thereof as in the other form of device. One conductor from the coil 31 passes directly to the battery 11 in the base, as previously described, and the other extends to the terminal 64 of the glass tube 32 (See Figs. 12 and 13).

edges 22 are Said tube has three terminals fused into the by the terminals 64, 65., That is to say, said magnet 36 moves quickly from one position to the other as the magnetized ring oscillates. There is less need for adjusting the position of the sealed tube 32 in this case, although by moving it upwardly as indicated in dotted lines, one circuit may be kept closed for a longer or shorter period of time and the other circuit is correspondingly and conversely regulated, i. e. if one circuit remains closed for short intervals of time, the other will remain closed for longer intervals and vice versa. The two positions of the controlling contacts in said sealed container are illustrated in Figs. 12 and 13 in conjunction with different positions of the magnetized rings.

This instrument has practically all the advantages of the one first described except that the circuit of the local battery is maintained closed for a longer proportion of the time than in the case of the first instrument, although the current consumption is so small in any case that the instrument is exceedingly efficient. On the other hand, it has the further advantage of no contacts exposed to air and of being simplified by the omission of the auxiliary contact and associated parts used with the first instru ment described.

Although in the second form of instrument described, the local circuit and the external circuits are controlled by contacts in the same evacuated tube, it is evident that said circuits may be independently controlled by means of separate evacuated tubes, and such arrangement is shown diagrammatically in Fig. 15 in which the right hand tube 32 may be assumed to control the local circuit, as a substitute for the exposed contacts shown in connection with Figs. 1 to 8 of the drawings, and the left hand tube controls the external circuit and may be substantially a duplicate of the tube and contact connection shown in Fig. 1. While both tubes may be adjustable, the adjustment of the left hand tube controlling the external circuit is the more important of the two. 1

Various other changes in the design and relative arrangement of parts may be made in the structures shown, without departing from the spirit of the invention.

I claim:

1. In combination, a ring shaped permanent magnet mounted to oscillate, an electromagnetic winding surrounding the same, contacts in the circuit of said winding, one of which is actuated by the oscillations of said magnet to energize said winding at intervals and maintain said oscillations and a magnetically operated switch adjacent said magnet to open and close a circuit under the influence of said magnet as it oscillates.

2. In combination, a ring shaped permanent magnet mounted to oscillate, an electromagnetic winding surrounding the same,.contacts in the circuit of said winding, one of which is actuated by the oscillations of said magnet to energize said winding at intervals and maintain said oscillations, a sealed container adjacent the path of movement of said magnet, a permanent magnet movably mounted therein, contacts opened and closed by the movement of said enclosed magnet and terminals extending through said sealed container for an external circuit.

3. Apparatus as in claim 2 wherein the sealed container is adjustable with respect to said ring shaped magnet to vary the timing of the opening and closing of the contacts in said container.

4. Apparatus as in claim 2 with means for varying the period of oscillation of said ring shaped magnet to regulate the timing of said enclosed contacts;

5. In combination, apermanent magnet in the form of a split ring, a supporting member secured thereto, a pivotally mounted shaft associated therewith to support said magnet above its center of gravity whereby it may oscillate, an electromagnetic winding adjacent the middle of said magnet, contacts in the circuit of said electromagnet, one of said contacts being carried by said shaft, the other being mounted to be engaged with a wiping action whereby said electromagnet is energized for short intervals of time to maintain the oscillations of said magnet after the same have begun, an evacuated glass tube mounted adjacent said magnet, a permanent magnet movably mounted therein in position to be influenced by the oscillations of said first magnet and circuit contacts controlled by the movement of said second magnet.

6. In combination, a permanent magnet in the form of a split ring, a supporting member secured thereto, a pivotally mounted shaft associated therewith to support said magnet above its center of gravity whereby it may oscillate, an electromagnetic winding adjacent the middle of said magnet, contacts in the circuit of said electromagnet, one of said contacts being carried by said shaft, the other being mounted to be engaged with a wiping action whereby said electromagnet is energized for short intervals of time to maintain the oscillations of said magnet after the same have begun, an evacuated glass tube mounted adjacent said magnet, a permanent magnet movably mounted therein in position to be influenced by the oscillations of said first magnet, and circuit contacts controlled by the movement of said second magnet, a support for said shaft of said first magnet and a support for said glass container adjustable with reference to said first support whereby the movement of said second magnet under the infiuence of said first magnet may be varied.

7. A device of the class described comprising an electromagnetic winding, a split ring permanent magnet passing through an opening therein, and pivotally mounted whereby it may oscillate, the ends of said magnet constituting like poles and the middle thereof being of opposite polarity and positioned normally within said winding, whereby energization of the latter will tend to rotate said ring.

8. A device of the class described comprising an electromagnetic winding, a split ring permanent magnet passing through an opening therein, and pivotally mounted whereby it may oscillate, the ends of said magnet constituting like poles, the middle thereof being of, opposite polarity and positioned normally within said winding, whereby energlzation of the latter will tend to rotate said ring, and separable contacts actuated by the movement of said ring magnet for opening and closing the circuit to said wind- -ing at intervals to maintain said oscillations.

contacts, in circuit with said electromagnetic winding, to control the energization of the latter and maintain said oscillations.

10. A device of the class described comprising a base, a high resistance coil of fine wire mounted above said base, a'split ring permanent magnet passing through said coil and pivotally mounted above its center of gravity whereby it may oscillate, the ends of said magnet constituting like poles and the middle thereof being of opposite polarity, a sealed container adjacent said ring and having three terminals through the wall thereof, two contacts within the same being connected to two of said terminals, a pivoted permanent magnet connected to said third terminal, a contact carried by said magnet to engage either of said first contacts as said magnet oscillates under the influence of said ring magnet, one of said two contacts and said third terminal being connected in the circuit of said coil to energize said coil intermittently, and the remaining contact and said third terminal being connected to an external circuit, opened and closed intermittently in timed relation to the oscillations of said ring magnet.

11. A device of the class described comprising a base, a support on said base, a horizontal shaft having knife edges engaging on said support, a split ring of magnetic material supported on said shaft with the opening in said ring at the bottom, a weight adjustably supported on said shaft in said opening whereby said magnet may oscillate at various predetermined intervals, a contact mounted on said shaft to oscillate therewith, a pivoted contact mounted to be engaged by said first contact during the swing thereof in one direction but not in the other, a flexible conducting member connected with said pivoted contact, a magnet coil surrounding said ring magnet but out of contact therewith, a circuit from one terminal of said coil to said shaft and from the other terminal thereof to said flexible conducting member, to complete the circuit to said coil during the engagement of said pivoted contact with said first contact, whereby the oscillations of said shaft and the parts carried thereby are maintained by the CERTIFICATE Patent No. 1,970, 412.

actuated by the oscillations of said magnet to energize said winding at intervals and maintain said oscillations, and a magnetically operated switch adjacent said magnet to open and close a circuit under the influence of said magnet as it oscillates.

13. In combination, an are shaped permanent magnet -mounted to .oscillate, an electro-magnetic winding surrounding the same and contacts in the circuit of said winding, one of which is actuated by the oscillations of said magnet to energize said winding at intervals and maintain said oscillations.

14. In combination, an are shaped permanent magnet mounted to oscillate, an electro-magnetic winding surrounding the same, a sealed tube mounted adjacent said magnet and having magnetically controlled contacts therein actuated by the oscillations of said are shaped magnet and a second sealed tube also mounted adjacent said magnet and containing magnetically actuated contacts, in circuit with said electro-magnetic winding, to control the energization of the latter and maintainsaid oscillations.

15. In combination, an are shaped permanent magnet mounted to oscillate, an electro-magnetic winding surrounding the same, a sealed tubed mounted adjacent said magnet and having magnetically controlled contacts therein actuated by the oscillations of said are shaped magnet and a second sealed tube also mounted adjacent said magnet and containingmagnetically actuated contacts.

. CLIFFORD V. BATES.

OF CORRECTION.

August 14, 1934.

CLIFFORD V. BATES.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 5, line 25, claim 11, after "engaging" insert bearings; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 11th day of September, A. D. 1934.

(Scull Leslie Frazer Acting Commissioner of Patents. 

